At a generic quantum critical point, the thermal expansion alpha is more singular than specific heat c(p). Consequently, "Grüneisen ratio," Gamma=alpha/c(p), diverges. When scaling applies, Gamma approximately T(-1/(nu z)) at pressure p=p(c), providing means to measure dimension of most relevant operator that couples to; in alternative limit T-->0 and p not equal p(c), 1/(p-p(c)) with prefactor is, up molar volume, simple universal combination exponents. For magnetic-field driven transition,...

We present low-temperature volume thermal expansion, beta, and specific heat, C, measurements on high-quality single crystals of CeNi2Ge2 YbRh2(Si0.95Ge0.05)(2) which are located very near to quantum critical points. For both systems, beta shows a more singular temperature dependence than thus the Grüneisen ratio Gamma proportional beta/C diverges as T-->0. CeNi2Ge2, our results in accordance with spin-density wave (SDW) scenario for three-dimensional spin fluctuations. By contrast, observed...

We propose that the "hidden order parameter" in URu2Si2 is a helicity must arise if Pomeranchuk criteria for spin-antisymmetric Landau parameters with respect to stability of Fermi liquid state are violated. In simple model, we calculate specific heat, linear and nonlinear magnetic susceptibilities, change transition temperature field such an parameter, obtain quantitative agreement experiments terms two extracted from data. The peculiar dependence NMR linewidth nature loss excitations...

Electrochemical impedance spectroscopy (EIS) is a technique for electrochemical characterization that sensitive to the battery state and can uncover multidimensional evolution information within battery. Lithium-ion batteries usually need be used in conjunction with power conversion circuits, while conventional EIS testing conducted offline time-consuming, which cannot effectively monitor characteristics during use. To match of square wave signal switching, rapid measurement method...

We consider the critical properties of Bose-Fermi Kondo model, which describes a local moment simultaneously coupled to conduction electron band and fluctuating magnetic field, i.e., dissipative bath vector bosons. carry out an $\ensuremath{\epsilon}$ expansion higher than linear orders. (Here is defined in terms power-law exponent bosonic-bath spectral function.) An unstable fixed point identified not only spin-isotropic case but also presence anisotropy. It marks where weight resonance has...

Recent experiments suggest quantum interference effects in the Coulomb drag of double-layer graphene systems. By accounting for correlated interlayer impurity scattering under a weak magnetic field, our theoretical results reveal resistivities resembling those (anti)localization. It is established that effect most significant when chemical potentials two sheets match. The theory clarifies roles intra- and Berry phases systems helps delineate intervalley contributions. These insights are...

We numerically study the thermoelectric transports of Dirac fermions in graphene presence a strong magnetic field and disorder. find that transport coefficients demonstrate universal behavior depending on ratio between temperature width disorder-broadened Landau levels (LLs). The transverse conductivity alpha{xy} reaches quantum value at center each LL high regime, it has linear dependence low temperatures. calculated Nernst signal peak central with heights order k{B}/e, changes sign near...

The distinguishing feature of a quantum system is interference arising from the wave mechanical nature particles which clearly central to macroscopic electronic properties. Here, we report signature effect in inter-layer transport process. Via systematic magneto-drag experiments on graphene-based double-layer systems, observe low-field correction Coulomb-scattering-dominated drag resistance wide range temperature and carrier density, with its characteristics sensitive band topology graphene...

Studies of non-Fermi liquid properties in heavy fermions have led to the current interest Bose-Fermi Kondo model. Here we use a dynamical large-N approach analyze an SU(N)xSU($\kappa N$) generalization We establish existence this limit unstable fixed point when bosonic bath has sub-ohmic spectrum ($|\omega|^{1-\epsilon} \sgn \omega$, with $0<\epsilon<1$). At quantum critical point, scale vanishes and local spin susceptibility (which is finite on side for \kappa <1) diverges. also find...

While single-layer graphene shows extraordinary phenomena which are stable against electronic interactions, the noninteracting state of bilayer is unstable to infinitesimal interactions leading one many possible exotic states. Indeed a gapped found in experiments but none states proposed so far can provide full accounts its properties. Here we show that magnetoelectric (ME) consistent with experimental observations. This breaks time-reversal symmetry through pair spontaneously generated...

We use quantum Monte Carlo simulations to calculate the phase diagram and correlation functions for transitions in two-dimensional dissipative XY model with without fourfold anisotropy. Without anisotropy, describes superconductor-to-insulator transition dirty superconductors. With represents loop-current order observed underdoped cuprates its fluctuations, as well fluctuations near ordering vector simple models of itinerant ferromagnets antiferromagnets. These calculations test an analytic...

With a method to systematically tune the mobility of same graphene devices, we have investigated dependence magnetothermoelectric transport properties on carrier mobility. In zero magnetic field, find that, as increases, Seebeck coefficient ${S}_{xx}$ exhibits more pronounced diverging trend near Dirac point. an external regular oscillations in are identified corresponding quantized Landau levels. Only high-mobility states does extra pair peaks and dips emerge point that persists, at least,...

We consider the scaling behavior of thermodynamic quantities in one-dimensional transverse field Ising model near its quantum critical point (QCP). Our study has been motivated by question about thermodynamical signatures this paradigmatic system and, more generally, issue how criticality accumulates entropy. find that crossovers phase diagram temperature and (the nonthermal control parameter) obey a general ansatz, so does specific heat magnetic expansion coefficient. Furthermore,...

Earlier Monte Carlo calculations on the dissipative two-dimensional XY model are extended in several directions. We study phase diagram and correlation functions when dissipation is very small, where it has properties of classical 3D-XY transition, i.e., one with a dynamical critical exponent $z=1$. The transition changes from $z=1$ to class criticality $z\ensuremath{\rightarrow}\ensuremath{\infty}$ driven by topological defects, discovered earlier, beyond dissipation. also find that...

All the available data for dispersion and linewidth of single-particle spectra above superconducting gap pseudogap in metallic cuprates any doping have universal features. The is linear energy below a scale omega(c) constant above. cusp at mandates, due to causality, waterfall, i.e., vertical feature dispersion. These features are predicted by recent microscopic theory. We find that all can be quantitatively fitted theory with coupling lambda(0) an upper cutoff omega(c), which vary less than...

For two coupled Anderson impurities, energy scales are present to characterize the evolution from local moment state of impurities either interimpurity singlet or Kondo ground state. The high-energy scale is found deviate single-ion temperature and rather as Ruderman-Kittel-Kasuya-Yosida interaction when it becomes dominant. We find that scaling behavior associated physical properties this consistent with those a coherence defined in heavy fermion systems.

Graphene has been the subject of much research, with structural engineering frequently used to harness its various properties. In particular, concepts graphene origami and kirigami have inspired design quasi-three-dimensional structures, which possess intriguing mechanical, electronic, optical However, accurate controlling folding process remains a big challenge. Here, we report discovery spontaneous growth on h-BN substrate via adopting simple chemical vapor deposition method. Folded edges...

Considerable evidence exists for the failure of traditional theory quantum critical points (QCPs), pointing to need incorporate novel excitations. The destruction Kondo entanglement and concomitant effect may underlie these emergent excitations in heavy fermion metals -- a prototype system criticality but remains poorly understood. Here, we show how ferromagnetic single-electron transistors can be used study this effect. We theoretically demonstrate gate-voltage induced phase transition. is...

We numerically study the disorder effect on thermoelectric and thermal transport in bilayer graphene under a strong perpendicular magnetic field. In unbiased case, we find that has similar properties as monolayer graphene, i.e., Nernst signal peak at central Landau level (LL) with height of order ${k}_{B}/e$ changes sign near other LLs, while thermopower an opposite behavior. attribute this to coexistence particle hole LLs around Dirac point. When finite interlayer bias is applied band gap...

The angle-resolved photoemission spectroscopy studies on cuprates in the pseudogap region reveal an extraordinary topological transition which ground state changes from one with a normal Fermi surface to four points. Such is not possible without some symmetry breaking, allows interference between one-particle basis states that normally forbidden. We also show experimental results are quantitatively given any free parameters by theory and discuss implications of results.